1. Field of the Invention
The present invention relates to a tone generating apparatus for use in electronic musical instruments, such as a synthesizer, and electronic piano and an electronic organ, and more particularly, to a tone generating apparatus capable of executing pitch control in accordance with timbres.
2. Description of the Prior Art
There is a conventional electronic musical instrument which can selectively use a plurality of pitches.
For instance, Japanese Patent Laid-open No. 60-178493 discloses an electronic musical instrument capable of freely setting the pitch for each pitch name within one octave.
According to the disclosed electronic musical instrument, a pitch control value for alteration of the pitch is the amount of off pitch from the temperament expressed in terms of a cent value. The pitch control value is given from an operation panel.
As frequency numbers (values proportional to tone frequencies: hereinafter called "F numbers") used in a tone generating apparatus, there are only twelve pieces of data, C, C#, D, D#, E, F, F#, G, G#, A, A# and B, in the temperament.
In generating a musical tone, any one of the twelve pieces of data is multiplied by a predetermined value (frequency ratio) corresponding to a cent value as a pitch control value. Then, the pitch altered by the multiplication is accumulated. The result of the accumulation is shifted to a range according to octave information. Through the above operation, a musical tone with the desired pitch will be generated.
According to this electronic musical instrument, when the pitch control value is zero, for example, the predetermined value (frequency ratio) is "1.00000" and the stored temperament F number can be used directly. If otherwise, the corresponding temperament F number is multiplied by a predetermined value (e.g., "1.00579" for +10 cents).
The electronic musical instrument with the above structure has the following shortcomings.
(1) While pitch control is commonly possible for the same pitch name within each octave, independent pitch control for each octave or independent pitch control for all the keys is not possible. PA1 (2) Since there are twelve pieces of F number information (C, C#, D, . . . , A# and B), the capacity of the ROM which stores this information needs to be small. It is however necessary to provide a multiplier of about 16 bits by 16 bits to compute the cent offset, thus enlarging the hardware. PA1 timbre designating means for designating a timbre; PA1 key code generating means for generating a key code in accordance with a pitch; PA1 storage means for storing pitch control information associated with each key code to be generated by the key code generating means for each timbre designated by the timbre designating means; and PA1 control means for, when tone generation at a predetermined pitch is instructed, reading out pitch control information, specified by that key code generated by the key code generating means in accordance with the instruction and the timbre designated by the timbre designating means, from the storage means and determining a tone frequency based on the pitch control information and the key code to thereby perform tone generation control. PA1 timbre designating means for designating a timbre; PA1 key code generating means for generating a key code in accordance with a pitch; PA1 modulation designating means for designating modulation of a tone frequency; PA1 storage means for storing pitch control information associated with each key code to be generated by the key code generating means for each timbre designated by the timbre designating means; and PA1 control means for, when tone generation at a predetermined pitch is instructed, reading out pitch control information, specified by that key code generated by the key code generating means in accordance with the instruction and the timbre designated by the timbre designating means, from the storage means, performing an operation on the read pitch control information and modulation information of the tone frequency whose modulation is designated by the modulation designating means to prepare new pitch control information, and determining a tone frequency based on the new pitch control information and the key code to thereby perform tone generation control. PA1 timbre designating means for designating a timbre; PA1 key code generating means for generating a key code in accordance with a pitch; PA1 storage means for storing pitch control information associated with each key code to be generated by the key code generating means for each timbre designated by the timbre designating means; PA1 pitch designating means for designating pitch control information to be arithmetically combined with the pitch control information stored in said storage means; and PA1 control means for, when tone generation at a predetermined pitch is instructed, reading out pitch control information, specified by that key code generated by the key code generating means in accordance with the instruction and the timbre designated by the timbre designating means, from the storage means, altering the pitch control information by arithmetically combining it with the pitch control information designated by the pitch designating means, and determining a tone frequency based on the altered pitch control information and the key code to thereby perform tone generation control.
Japanese Patent Laid-open No. 61-194497 filed by the present applicant discloses a technique of selecting independent pitches in accordance with timbre parts.
As this technique cannot permit the selected pitch to be divided into finer pitches within a half tone for finer designation, the pitch data cannot be subjected to frequency modulation, such as vibrato.
Although independent pitches can be selected in accordance with timbre parts, it is a player who makes the selection and it is difficult even for skilled persons to select the desired timbre during a musical performance and simultaneously select the optimal pitch for that timbre.
The "pitch" in the above prior art is concerned with a so-called pitch theory, and it is determined to which one of typical pitches, for example, the temperament, pure temperament and Pythagorean pitch, the pitch in question is close for each timbre part.
Actually, however, individual instruments have their own unique pitches. In the case of a piano, for instance, the pitch-octave relation that the pitch is doubled between adjoining octaves is not fulfilled, but pitch setting with a so-called S curve is carried out so that a lower pitch is set in a high-pitch range while a higher pitch is set in a low-pitch range. It is therefore difficult to associate the S-curved pitch setting with existing, limited pitches.